1. Field of the Invention
The present invention relates to a line type recording head, and a recording apparatus which performs a recording operation for recording paper with use of the line type recording head.
2. Discussion of the Background
Heretofore, an ink jet printer head, a thermal printer head, and an LED head have been practically used as line type recording heads.
A line type recording head has plural recording elements arranged in a line and is attached to a recording apparatus in such a manner that the recording elements are arranged in a main scanning direction. The recording elements are driven selectively while recording paper is moved relatively in a sub scanning direction, to record a desired image on the recording paper.
In such a line type recording head, a maximum print width of the recording apparatus is determined by the arrangement length of the recording elements. Therefore, the line type recording head is generally popular as a recording head for recording paper of a narrow width, but is seldom used as a recording head for such a widely spread size of recording paper as A4 size. This is for the following reason. As the maximum print width increases, the arrangement length of recording elements must be made longer, but the longer the arrangement of recording elements, the more difficult the production of the recording head becomes or the lower the yield becomes.
In an effort to avoid such an inconvenience, there has been proposed such a method as is disclosed, for example, in Japanese Unexamined Patent Publication No. Hei 11-20176 in which plural head units are joined together to constitute a single recording head.
On the other hand, it is an important subject for the recording head to attain a high density of recording elements for achieving a high definition of recording. In this connection, as to a line type recording head, in the aforesaid publication Hei 11-20176 there are disclosed a method for attaining a high density of recording elements in which a recording head wider than the maximum recording width is disposed to be inclined with respect to a main scanning line or a method for attaining a high density of recording elements in which a recording head constituted by joining plural head units is disposed to be inclined with respect to a main scanning line.
The invention disclosed in the foregoing publication Hei 11-20176 is concerned with a method for uniforming the spacing of recording elements at the time of disposing a recording head to be inclined with respect to a main scanning line, the recording head being constituted by joining plural head units.
Such a conventional technique involves problems which will be described below. Reference has been made above to the method of attaining a high density of recording elements by disposing a recording head to be inclined with respect to a main scanning line, the recording head being constituted by joining plural head units. FIG. 1 is a schematic diagram showing an example of a recording head which adopts the high density realizing method. As shown in the same figure, a recording head 101 is constituted by joining plural head units 103 each having plural recording elements 102 arranged in a line, the recording head 101 being inclined with respect to a main scanning line 104.
However, the recording head 101 constructed as in FIG. 1 involves the problem that its size in a sub scanning direction, or paper feed direction, increases. The larger the number of head units 103 to be joined, the more conspicuous the increase in size in the sub scanning direction becomes, thus leading to an increase in size of the recording head 101 as a whole.
It is an object of the present invention to attain the reduction in size of a line type recording head which can effect a high definition recording by a combination of plural head units.
The object of the present invention is achieved by the novel recording head and recording apparatus using the recording head of the present invention.
According to the present invention there is provided a line type recording head comprising: a plurality of head units each having a substrate and a plurality of recording elements arranged on a virtual line on the substrate; and a head holder for positioning and holding at least one array units so that the recording elements in all of the head units are arranged at equal pitches in a main scanning direction, the array units being each constituted by a set of plural head units arranged to be inclined with respect to a main scanning line in such a manner that the recording elements arranged at the same position on the substrates of separate head units lie on the same main scanning line. According to this construction, since the recording head is constituted by a set of plural head units, the production of the recording head is easy and the yield thereof is high. Moreover, since each head unit is inclined with respect to a main scanning line, it is possible to effect a high definition recording. Further, since plural head units are arranged to be inclined with respect to a main scanning line so that the recording elements located at the same position on the substrates of separate head units are positioned on the same main scanning line, the size of the recording head does not become large in a sub scanning direction irrespective of the number of head units used.
According to the present invention there is further provided a recording apparatus comprising: a line type recording head; a scanning mechanism for moving the recording head and recording paper relatively in a sub scanning direction; and a drive control circuit for controlling the operation of the recording head. The line type recording head comprising: a plurality of head units each having a substrate and a plurality of recording elements arranged on a virtual line on the substrate; and a head holder for positioning and holding at least one array units so that the recording elements in all of the head units are arranged at equal pitches in a main scanning direction, the array units being each constituted by a set of plural head units arranged to be inclined with respect to a main scanning line in such a manner that the recording elements arranged at the same position on the substrates of separate head units lie on the same main scanning line. The drive control circuit includes a print timing controller which makes a delay control so that the recording elements in the head units not positioned on the same main scanning line operate on the same main scanning line. According to this construction, since the recording head is constituted by a set of plural head units, it is easy to produce the recording head and the production yield thereof is high.
Moreover, since the head units are arranged to be inclined with respect to the main scanning line, it is possible to effect a high definition recording. Further, since the plural head units are arranged to be inclined with respect to the main scanning line in such a manner that the recording elements located at the same position on the substrates of separate head units lie on the same main scanning line, the size of the recording head does not increase in the sub scanning line irrespective of the number of head units used.